Mount mkfs fix

Add a not_if to the mount def to avoid trying to mount the device again and throwing errors, modified the format def to use the same not_if

Error example running chef-client after the first time the volume is created and mounted:

    Recipe: elasticsearch::data
    * bash[Format device: /dev/xvdc] action run[2013-12-19T20:09:43-08:00] INFO: Processing bash[Format device: /dev/xvdc] action run (elasticsearch::data line 4)
    (skipped due to not_if)
    * directory[/usr/local/var/data/elasticsearch/] action create[2013-12-19T20:09:51-08:00] INFO: Processing directory[/usr/local/var/data/elasticsearch/] action create (elasticsearch::data line 16)
    (up to date)
    * mount[/dev/xvdc-to-/usr/local/var/data/elasticsearch/] action mount[2013-12-19T20:09:51-08:00] INFO: Processing mount[/dev/xvdc-to-/usr/local/var/data/elasticsearch/] action mount (elasticsearch::data line 23)

    ================================================================================
     Error executing action `mount` on resource 'mount[/dev/xvdc-to-/usr/local/var/data/elasticsearch/]'
    ================================================================================


    Mixlib::ShellOut::ShellCommandFailed
    ------------------------------------
    Expected process to exit with [0], but received '32'
    ---- Begin output of mount -t ext3 -o rw,user /dev/xvdc /usr/local/var/data/elasticsearch/ ----
    STDOUT:
    STDERR: mount: /dev/xvdc already mounted or /usr/local/var/data/elasticsearch/ busy
    mount: according to mtab, /dev/xvdc is already mounted on /usr/local/var/data/elasticsearch
    ---- End output of mount -t ext3 -o rw,user /dev/xvdc /usr/local/var/data/elasticsearch/ ----
    Ran mount -t ext3 -o rw,user /dev/xvdc /usr/local/var/data/elasticsearch/ returned 32